PIN FUNCTIONS

SO20L

Power DIP

Name

Description

11

SIGNAL SUPPLY VOLTAGE

Must be Connected to pin 3

22

OUTPUT

Regulator output

33

SUPPLY VOLTAGE

Unregulated voltage input. An internal regulator

powers the internal logic.

4, 5, 6, 7

14, 15, 16, 17

4, 5, 6

13, 14, 15

GROUND

Common ground terminal

87

POWER FAIL INPUT

Input of the power fail circuit. The threshold can be

modified introducing an external voltage divider

between the Supply Voltage and GND.

98

POWER FAIL OUTPUT

Open collector power fail signal output. This output

is high when the supply voltage is safe.

10

9

RESET DELAY

A capacitor connected between this terminal and

ground determines the reset signal delay time.

11

10

RESET OUTPUT

Open collector reset signal output. This output is

high when the output voltage value is correct.

12

11

REFERENCE VOLTAGE

Reference voltage output.

13

12

FEEDBACK INPUT

Feedback terminal of the regulation loop.

The output is connected directly to this terminal for

5.1V operation; it is connected via a divider for

higher voltages.

18

16

INHIBIT INPUT

TTL level remote inhibit. A logic low level on this

input disables the device.

19

17

C OSCILLATOR

Oscillator waveform. A capacitor connected

between this terminal and ground modifies the

maximum oscillator frequency.

20

18

R OSCILLATOR FREQ.

A resistor connected between this terminal and

ground defines the maximum switching frequency.

THERMAL DATA

Symbol

Parameter

SO20

Powerdip

Unit

Thermal Resistance Junction to Pins

max.

15

12

°C/W

Thermal Resistance Junction to Ambient (*)

max.

85

80

°C/W

(*) See Fig. 28

L4963 - L4963D

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